The human visual system is a complex system with a great ability to absorb vast amounts of information originating in many varying formats, including visual displays. Visual displays are found in varying sizes and forms in today's world, displaying many types of information, from large visual display screens announcing scheduling information found in airports, to small visual displays, such as those incorporated into pocket calculators. Included within these visual displays are direct view displays, including projection displays. Of concern in the use of projection displays is the display resolution quality and the maintenance of minimal power requirements and low manufacturing costs.
Of relevance in the maintenance of resolution quality, is the human visual system's ability to process and integrate information, and the speed at which the visual system is able to do so. One of the greatest problems associated with laser projection displays is "speckle" in the image due to the light reflecting off the screen, then interfering with itself, and causing "speckle" to the human eye. In theory, "speckle" is defined as the random intensity variation that is caused by the random interference of the light. Accordingly, a common solution to the problem of "speckle" in displays is to vibrate the screen at a high frequency, thereby causing the speckle pattern to change quickly and smooth out so the eye does not see it. This type of display requires the mechanical movement of the display screen, thus complex and costly to operate.
In theory, the human visual system can process and interpret information no faster than approximately 60 Hz. Therefore, by incorporating a display that has applied thereto a drive frequency, or voltage, so as to vibrate included liquid crystal molecules at a frequency higher than 60 Hz, "speckle" in the display can be eliminated. Accordingly, the human eye will average the speckle effect and the pattern will be smoothed out, i.e. no "speckle" will be observed. This process, can be utilized in the field of display technology through the use of liquid crystal projection displays, and more specifically in the development of enhanced resolution visual displays, including projection displays.
Thus, there is a need for a projection display that eliminates the need for mechanical movement of the screen to allow for the viewing of a high resolution image without speckle. Thus, disclosed is a display screen, including a liquid crystal material, that allows for the generation of a high resolution display, by applying a voltage to the liquid crystal molecules included therein, causing them to vibrate slightly, and thereby smooth out the "speckle" typically observed.
Accordingly, it is highly desirable to provide for a projection display in which included is a liquid crystal material capable of undergoing a reaction in the presence of a drive frequency, and thereby eliminating "speckle" when viewing the display.
It is a further purpose of the present invention to provide a new and improved non-speckle laser display in which no mechanical movement is involved in the generation of a projection display.
It is yet a further purpose of the present invention to provide a new and improved non-speckle laser display in which a projection display screen including a liquid crystal material, having a high frequency, low voltage applied thereto provides for a non-speckle, high resolution image.
It is still a further purpose of the present invention to provide a new and improved non-speckle laser display system that includes a laser image source and a projection display screen including a liquid crystal material, for the generation of a non-speckle, high resolution image.
It is a purpose of the present invention to provide a new and improved projection display system including a laser diode image source and a liquid crystal projection screen for use in videoconferencing systems, cellular phones, personal digital assistants (PDAs), pagers, portable computers, or the like.